Short wave receiving circuit



Sept. 3, 1935. I w. LUDENIA 2,013,103

SHORT WAVE RECEIVING CIRCUIT I Filed Aug. 23, 1950 g," Q d in Q5'INVENTOR WERNER LUDEMA" ATTORNEY Patented Sept. 3, 1935 PAT NroFricE2,013,103 snoar WAVE RECEIVING oracnrr Werner Ludenia, Berlin, Germany,assignor to Radio Corporation of America, acorporation of Delaware iApplication August 23, 1920,. Serial No. 477,344

Germany December 10, 1929 10 Claims. (01. 250-20) There "are knownshort-wave receiving circuits wherein there is used an electronic tubeor electron discharge device in the so-called Barkhausen-Kurzconnection; i. e. with a grid or control electrode impressed with a highpositive potential and a plate having a lower potential and wherebyone-half of a dipole is connected to the grid or the cathode.

By experimental have found that it is advantageous to usel instead of adipole an antenna which is tuned to M2. To one end or to both ends ofthis antennaI connect the plate of one tube each. The potential supplyto the plate of the tube is accomplished from the electrical mid-pointof theantenna.

As required by the revised statutes, my invention is defined in theappended claims. However,it may bestbe understood both as to its- 0wherein the anode of an electron discharge device is maintainedat arelatively negative potential, and has connected directly theretoa halfwave length conductor to whose'voltage nodal point there is suppliedanode potential,

1 Figure2illustrates a pair of electrondischarge devices having cathodesenergized as in Figure 1 and having a half wave length conductorconnected to the anodes of the tubes such that the tubes'act inpushpullfashion, and, A Figure '3 illustrates an arrangement similar to thatshown in Figure 1 wherein the lead-in wire to the anode forms apart ofthe antenna.

In Figure 1 there is the antenna a which is connected at one endwith theanode or plate ofelectron discharge device or tube 1'. To theelectricalmid-point p of the antenna is connected the potential fortheplate through a choke coil' 03. The end'q of the antenna is left openended or electrically free.

Good reception on ultra short wave lengths riations in amplitude of thelocally generated waves will in turn cause marked changes in anodecurrentflow corresponding to the modulation of the transmitted Waves,These relatively low frequency variations may be taken from the platecircuit by means of a suitable transformer 2 amplifiedb-y a suitableamplifier 4 and translated by any suitable translating device such asthe illustrated telephone ii.

In Figure 2 both ends of the antenna .a are connected with a plate ofeach of the tubes 1'1 and 72 which act in pushpull fashion. Thepotential supply to the plates is likewise accom plished through a choked.

The electron discharge devices shown in Figure 2 are connected and actin pushpull fashion since the extremities of antenna a are always atvoltage maximums of opposite polarity. Here also operation oftranslating device 6 coupled to the anode supplycircuit through-anamplifier i and transformer 2 may be obtained by adjustment of thepotentials such that the system is on the verge of oscillation.Signalling waves will produce variations in anode energy flow as aresult of which there will be modulation indication in the translatingdevice 6.

It is suitable to use also a tube with standard base in the manner thata part of the antenna is" formed by the lead-in wires of the tubecapacitatively coupled with one another. In Figure 3,

R isthe tube, whose lead-in wires form a part of the antenna a. Thetranslatingdevice 6 is here shown as directly connected in the anodesupply lead. The overall length a should, of course, be one-half wavelength. The length of anode lead between the anode and voltage nodalpoint]? should be chosen such that the overall length a, of the antennais one-half wave length and such that point P is at a voltage nodal orcurrent maximum point.

Arrangements according to the present invention are especially suitablefor the directional reception of short waves whereby the minimum ofreception isobt ained when the arrangement pointswith its'longitudinalaxis towards the transmitting station, but the maximum of tree. ceptio'nthetransversal position; or, in a direction at right angles to the linebetween the receiver and transmitter.

Although the systems described are particularly useful for reception ofshort waves, it is clear that they may also be used for the transmissionof signals on electromagnetic wave energy. In that event, translatingdevice 6 may be replaced by a source of modulating energy which in turnis amplified by a suitable amplifier such as amplifier 4 and fed to theanode circuit of the devices.

I claim:

1. In combination, an electron discharge device having a cathode, ananode and a control electrode, energy means in circuit with said cathodefor maintaining said control electrode at a relatively positivepotential and said anode at a lower potential with respect to saidcathode, a half wave length conductor directly connected to said anodeand a connection from the electrical midpoint of said half wave lengthconductor to said energy means, whereby said anode is maintained atsuitable potential through said connection and conductor.

2. An ultra short wave length receiving system comprising an electrondischarge device having a cathode, an anode and a control electrode, asource of energy in circuit with said cathode for maintaining saidcontrol electrode at a positive potential with respect to said cathode,a half wave length antenna directly connected to said anode, anothersource of energy in circuit with said cathode and a connection betweensaid last source and the midpoint of said half wave antenna formaintaining said anode at a negative potential with respect to saidcathode, and a utilization circuit coupled to said connection.

3. Apparatus as defined in claim 2 including a high frequency choke coilin said connection, and a transformer for coupling to said utilizationcircuit.

4. In ultra short wave length electrical apparatus, the combination witha pair of electron discharge devices having anodes, cathodes, andcontrol electrodes, and energy means for maintaining said anodes andcontrol electrodes at relatively negative and highly positivepotentials, respectively, with respect to their respective cathodes, ofa half wave length conductor directly connected to the anodes of theelectron discharge devices, and a connection from substantially themidpoint of said half wave length conductor to said energy means.

5. In combination, a plurality of electron discharge devices havinganode, cathode and control electrodes, connections between therespective corresponding electrodes of said devices,,the connectionbetween said anodes comprising an energy collector, a source of energyconnected to said control electrodes of said devices for maintainingsame at a positive potential relative to their respective cathodes,another source of energy, a connection including a high frequency chokecoil extending between said last source and the electrical midpoint ofsaid energy collector for maintaining said anodes at a lower potentialthan that on said control electrodes relative to their respectivecathodes, and a utilization device eleotromagnetically coupled to saidlast connection.

6. In ultra short wave length electrical apparatus, the combination of aplurality of electron discharge devices having anodes, cathodes andcontrol electrodes, a source of energy having its positive terminalconnected to said control electrodes, another source of energy, a halfwave length conductor connected directly to the anodes of said electrondischarge devices, and a connection between the negative terminal ofsaid last source and the midpoint of said half wave length conductor forsupplying potentials to the anodes of said devices.

7. In ultra short wave length electrical apparatus, a pair of electrondischarge devices having anode, cathode and control electrodes,connections between said respective corresponding electrodes of saiddevices, the connection between said anodes comprising a half wavelength conductor, a source of energy connected to the control electrodesof said devices for maintaining same at a positive potential relative tothe respective cathodes, a source of energy,and a connection betweensaid last source and the midpoint of said half wave length conductor formaintaining said anodes at a potential lower than that on said controlelectrodes relative to their respective cathodes, and a relatively lowfrequency circuit coupled to said last connection.

8. In high frequency apparatus, an electron discharge device having acathode, an anode and a control electrode, a source of direct currentpotential directly connected to said control electrode for maintainingsame at a positive potential with respect to said cathode, a half wavelength conductor connected to said anode, another source of directcurrent potential and a connection from said last source to said halfwave length conductor for maintaining said anode at a relativelynegative potential with respect to said cathode, said half wave lengthconductor being arranged to include as a portion thereof the length ofthe lead-in structure to the anode, and a relatively low frequencycircuit coupled to said connection.

9. An ultra short wave length receiving system comprising an electrondischarge device having an anode, cathode, and a grid, means formaintaining said grid at a positive potential and said anode at a muchlower potential with respect to said cathode, an antenna having one endconnected to said anode, a supply lead from the electrical midpoint ofsaid antenna to said means for supplying said anode with potential, aninductance in said supply lead, and an output circuit coupled to saidanode supply lead.

10. In combination, an electron discharge device having an anode,cathode, and control electrode, means for maintaining said controlelectrode at a positive potential with respect to said cathode, and saidanode at a potential much less than said control electrode potential, anenergy collector in circuit with said anode and a connection from avoltage nodal point on said collector to said means, whereby said anodeis supplied with potential through said connection and collector.

1 WERNER LUDENIA.

